DJ54, I see you use red plastic cups the same as I do, We sure did have a lot of rain last year here in PA also, Just plowed my garden on 3-19-2019, Now I need it to dry out nice since my cabbage, broccoli and cauliflower plants are getting big and need planted, My garden did good last year except for the zucchini, some darn bug must have gotten them because every single plant was killed, Looked good 1 day then go out the next and it is dying that fast.
Yeah, I like to think of it as recycling my drink cups. I like them because it allows a little room for root growth, and not get so root bound, if I'm a little late getting them out due to the weather.
We had a record rain fall total last year. It took until the last week of Dec., but we broke it. I lost 4 dozen tomato plants, and about the same of various pepper plants. I lost all of the Carolina Reapers. The rain literally beat them into the ground, snapping the stems off.
It sounds as though you had some vine borers attack your Zucchini. Usually when you see them start to wilt, it's already too late. Here's a link to The Old Farmers Almanac explaining what they are, and some prevention's. https://www.almanac.com/pest/squash-vine-borer
If you happen to use the diatomaceous earth, if you have a feed mill near by, you can buy a 50 lb. bag for just a couple of bucks more than what a big box store wants for 10 lbs. Just be sure to wear a dust mask when sprinkling it on. I have a friend in his early 80's, that uses's garden lime to sprinkle on a lot of his plants to keep pest's away. Even sprinkles it on his cabbage heads to keep the cabbage worms of of them.
I'm going to try BT this year on some cabbage, and tomatoes, since my buddy's son who works for the Ohio Dept. of Agriculture, swears BT is perfectly harmless. I'll probably do the lime thing on the cabbage too, for double prevention. I do recall seeing more than several Zucchini patches in my travels, with the leaves and stems dusted with lime, just about the time they start to bloom, so I'll give it a shot..